WAVERLY GROUP. 73 



of his. Of Goniatites, I collected three different species. Some 

 seams contain also numerous casts of bivalve shells, most of 

 them identical with forms found in the sandstones of Marshall 

 and Battle Creek. Carbonaceous vegetable fragments, among 

 them Calamites and Lepidodendron, are of common occurrence. 

 The lower beds of the sand rock are largely intermingled with shale 

 fragments, and the underlying shales being eroded on the surface, 

 the sand rock resting on them fills out their furrows. 



In the bluffs on the lake shore, below the solid body of sand rock 

 which is designated as the grindstone, a series of blue shales, inter- 

 laminated with seams of sandstone, is exposed, emerging about 5 

 or 6 feet above the water-level. Similar shaly beds are noticed in 

 the bed of Willow Creek, under the mill at Huron City. At that 

 locality the sand-rock ledges much prevail over the shaly material, 

 certain seams of this sand rock being completely filled with the casts 

 of a Rhynchonella, intermingled with a species of Productus and 

 a few other shells. The surface of some layers is often covered 

 with relief forms resembling Fucoides caudagalli. On the south side 

 of Willow Creek, the hill over which the road to Port Hope leads is 

 again capped by the grindstones. The hill forms toward the lake 

 a steep escarpment about 50 feet high, which continues southward 

 about a mile beyond Point of Barques Lighthouse. Twenty feet 

 of the top part are solid sandstone ledges, containing irregular 

 seams of conglomeratic structure ; the lower portion of the escarp- 

 ment, down to the level on which the lighthouse stands, is made 

 up by arenaceous shales, alternating with seams of sand rock. The 

 shales contain casts of bivalves and other fossils, similar or identi- 

 cal with those found in a bed of calcareous sand rock below them, 

 the same on which the lighthouse is built. 



This sand-rock ledge, having a thickness of from 2 to 3 feet, is 

 even with the water-level a few hundred yards north of the light- 

 house ; at the lighthouse it has risen about 5 feet, and further 

 south it may be seen in the bluffs 8 or 10 feet higher than the 

 level of the lake. The shale bluffs above the sand-rock ledge are 

 at a distance from shore at the lighthouse and north of it ; a quar- 

 ter of a mile south of the lighthouse, however, they come up close 

 to the shore line, and cover the ledge from above, while below it, 

 as basal part of the same bluffs, shale beds similar to the upper 

 ones make an outcrop. These bluffs continue for about half a 



